Illustrated herein are embodiments of a timing belt drive system for motorcycle engines, and more specifically a camshaft timing belt drive system for air cooled Twin Cam V-Twin motorcycle engines.
Air-cooled V-Twin motorcycle engines, such as the Twin Cam engine used in Harley Davidson® motorcycles have used a chain drive system or gear drive system for driving, or rotating, the camshafts with the engine crankshaft. The chain drive system uses a drive chain connected to the engine crankshaft via a crankshaft sprocket. The drive chain is also connected to a camshaft sprocket which is connected to the camshafts thereby transferring drive forces from the crankshaft to the camshafts for turning the camshafts during engine operation. A chain tensioner having a spring biased pad, or shoe, rides against the chain between the two sprockets to apply tension to the chain. The chain tensioner pad typically wears during use due to this contact with the chain.
Gear drive systems have also been used for driving the camshafts from the crankshaft by using a camshaft sprocket having teeth meshing with the teeth of the crankshaft sprocket. These camshaft gear drive systems can induce gear whine and other undesirable noises during operation.
The present invention contemplates a new and improved camshaft drive system that resolves the above-referenced problems and others.